Robot fish powered by seawater can dive to the deepest point in the oceans; 32,800 feet

Researchers from China's Harbin Engineering University have come up with a novel, deep-sea soft robot that swims like a fish and looks like one — all powered by the ocean itself. The bionic robot — detailed in a paper published in Science Robotics — is designed for the observation of delicate marine ecosystems up close without disturbance.

The scientists behind this creation came up with a novel electrohydraulic system, eliminating the bulky, rigid motors used in conventional submersibles, which are prone to damage. The robot is about 32 centimeters (12.6 inches) long and weighs in at about 670 grams (1.5 lbs). It has flexible structures on its sides that use the natural ions in the surrounding seawater to create an electric field. This electric field causes a special fluid inside the robot's silicone body to move from side to side, propelling the robot just like a real fish.

This groundbreaking design allows the robot to withstand extreme conditions. The internal fluid and flexible structure automatically balances the pressure of the deep sea. In field tests, the robot dived to a depth of 4,000 meters (13,123 feet). The team also said it has passed pressure tests in the laboratory for a depth of 10,000 meters (32,808 feet), withstanding temperatures as low as 2° C (35.6° F). To put this is perspective, the deepest part of the ocean — Challenger Deep — is only 10,935 meters (35,876 feet) deep.

Equipped with a camera and optical sensors, the robotic fish is well-suited for low-profile exploration and biodiversity studies in previously inaccessible deep-sea environments.